Solar cell modules include a solar cell, an encapsulant layer that encapsulates the solar cell, a surface-protecting layer, and a back sheet. The encapsulant layer and the back sheet are preferably firmly bonded to each other. For back sheets including components such as a back-reinforcing material, a water-impermeable sheet, and a substrate sheet and a film, the components and the film need to be firmly bonded to each other. In order to achieve such bonding performance, some techniques are proposed.
Patent Literature 1 discloses a solar cell module including a solar cell embedded in a filler on a back-reinforcing material, wherein the surface of the back-reinforcing material in contact with the filler is coated with epoxy resin.
Patent Literature 2 discloses a solar cell substrate with excellent adhesiveness including a metal plate as a substrate and a film formed from a coating composition, wherein the coating composition contains a polyvinylidene fluoride-based fluororesin free from a functional group, and a tetraalkoxysilane or a partially hydrolyzed condensate of a tetraalkoxysilane in an amount of 0.5 to 100 parts by mass for each 100 parts by mass of the coating resin, and the partially hydrolyzed condensate of a tetraalkoxysilane is oriented to the film surface.
Patent Literature 3 discloses a back sheet for a solar cell module, including a water-impermeable sheet and, on at least one side of the water-impermeable sheet, a cured film formed from a fluorine-containing polymer coating containing a curable functional group.
Patent Literature 4 discloses a back sheet for a solar cell module, including a substrate sheet and, on one or both sides of the substrate sheet, a cured film layer formed from a coating containing a fluorine-containing polymer (A), wherein the polymer (A) contains a repeating unit based on a fluoroolefin (a), a repeating unit based on a crosslinkable group-containing monomer (b), and a repeating unit based on an alkyl-containing monomer (c) in which a C2-C20 linear or branched alkyl group free from a quaternary carbon atom and a polymerizable unsaturated group are linked via an ether bond or an ester bond.